1. Field of the Invention
The present invention relates generally to apparatus or systems for confining and collecting oil spills on a body of water and, more particularly, to a ship-mounted oil recovery apparatus that confines oil discharge in an area immediately surrounding the ship and includes recovery apparatus for collecting and storing recovered oil in auxiliary storage enclosures that can be placed in the water. The storage enclosures can be either towed by the ship or set adrift for later pick up by other recovery vessels. The present invention also relates to the method of containing oil discharge near a ship and recovering the same.
2. Description of the Prior Art
Various methods and apparatus have been developed for the rapid confinement and collection of oil spills on waterways due to the extreme and long-lasting damage that the released oil can inflict on marine life and shorelines. One obvious way of preventing the damage caused by oil spills is through better engineering and construction of oil-carrying ships or vessels to minimize breakage of their oil-storage compartments. However, even the best engineered ships are susceptible to unforeseeable disasters such as collisions with other ships, unchartered reefs and similar objects, and even acts of war which can cause the best-made ship to spew a portion, and sometimes all, of its oil cargo into the water.
Once a ship has been damaged and is discharging oil, the key factor in minimizing environmental damage is through quick containment of the spill to a relatively small area, if possible, for later recovery. For this reason, various confinement apparatus such as floating conduits or booms have been developed which can be transported by helicopter or other ship for deployment around the oil slick until suitable recovery apparatus can be implemented to remove the oil. These floatable boom-type devices usually include a floatable upper portion and lower skirt portion that remains submerged in the water to prevent oil from passing under the device. The device acts in some respects as a floating fence to confine the oil spill within a defined enclosure. While somewhat useful, these devices have several disadvantages discussed below which reduce their effectiveness.
Other ways of dealing with oil spills is through quick recovery along with some measure of containment. In this regard, numerous devices and methods have been designed to recover oil floating on the top surface of the water. For example, specialized skimmers have been placed on smaller, more mobile recovery boats which can move along the water to skim and channel the uppermost oil layer into a collection area where a pump or similar device can transport the oil to holding tanks. Other solutions include flotation suction devices that can be placed in an oil spill and allowed to retrieve a portion of the oil that floats on the water. The recovered oil can be pumped into holding tanks that are located near the suction device.
All of these above-mentioned devices have varying degrees of success in the confinement and recovery of discharged oil. The rate of success, at times, can be totally dependent upon the conditions of the water during the recovery operation. For example, many of the skimming-type recovery boats can not be utilized if wave conditions on the body of the water are too high. Flotation-type suction apparatus also have inherent problems if the water current is too rapid. Still other problems include inaccessibility of the specialized recovery boats in shallow waters or in areas having obstructions floating in, or near, the spill.
These above-mentioned problems are compounded by the fact that these skimmer-type recovery boats and confinement devices usually have to be brought out to the damaged ship after oil discharge begins. In certain situations, the damaged ship can be, and often is, hundreds of miles away from these recovery crafts and confinement devices. In some instances, the oil slick can spread many miles away from the damaged ship before recovery help is received. When this occurs, much more oil is dispersed over a larger area, making recovery more difficult and expensive to accomplish.
As a result of these disadvantages and shortcomings of prior art oil containment and recovery systems and apparatus, it would certainly be advantageous to have a system or apparatus which can be carried on board the ship for quick deployment that allows for quick containment of oil in an area immediately near a damaged ship. Such an apparatus would certainly decrease the possibility of producing long or expansive oil slicks and would reduce some of the problems in recovering the discharged oil. Additionally, such a confinement apparatus would be even more valuable if immediate recovery could also be implemented. Such an apparatus could also reduce the number of recovery boats and other devices that would have to be utilized during the recovery operation. As a result, oil recovery can be done more efficiently and less costly, and more importantly, such an apparatus, in all likelihood, would reduce the possibility that the discharged oil will cause long-standing damage to the environment.